1. Field of the Invention
This invention relates to a method of optically reading data out of a record medium and, more particular, to a method of optically reading data recorded along concentric or spiral equidistant data tracks on a disk-shaped record medium, by means of a planar apertured probe array at a high speed without tracking control.
2. Related Art Statement
There has been proposed a method of optically reading data out of a record medium by means of a near-field optical probe which is arranged in a very close vicinity of the record medium. In this method, evanescent light generated from the probe is interacted with a recording surface of the record medium to generate scattered light. An intensity of the scattered light is modulated in accordance with a crenellated structure of a recording surface of the record medium. Therefore, by detecting a change in an intensity of the scattered light, the date can be reproduced. It has been probed that such a near-field optical reproducing method can realize ultra high density recording of an order of 1 Tbit/inch.
In the known method, the probe provided in a recording and/or reproducing head is formed by an optical fiber having a sharp core tip. In the known method, high speed sweeping or scanning is impossible, because the tip of the probe is fragile mechanically and the throughput of the light is low. In addition, it is difficult to perform a tracking control for the data tracks having a very small width of several ten-nm width.